Skin metastases from prostate cancer associated with malignant melanoma.

A 66-year-old man, admitted to the hospital for prostatic carcinoma, presented with a nodular lesion located on the presternal region and a small nodule (0.5 cm in diameter) simulating a scalp sebaceous cyst located on the scalp. Moreover, an irregular darkbrown lesion was observed on the left side of the abdomen, and a brownish macula was also present on the presternal region. Histologic examination of the two nodular lesions revealed cutaneous metastases from prostatic carcinoma. The pigmented lesion, localized on the abdomen, proved to be a superficial spreading melanoma with a maximal depth of 1.36 mm. Histologic examination of the brownish lesion on the presternal region revealed nevus cell nests within the epidermis and in the dermis. We discuss the propensity of developing a secondary cancer in a patient with a primary malignancy.